一起由腺病毒B3和E4引起的呼吸道感染疫情的流行病学调查

Epidemiological investigation on an epidemic of respiratory infection in schools caused by Adenoviruses B3 and E4

目的调查一起学校发生的呼吸道感染暴发疫情的流行病学特征及其病因。方法对学校呼吸道感染病例进行回顾性流行病学分析,采集患儿的咽拭子标本进行呼吸道病毒核酸检测,腺病毒(Adenovirus,AdV)阳性标本扩增六邻体基因并测序。结果所有病例全部在学校,涉及2个班级,二(3)班12例、三(4)班13例,均在2号教学楼二楼、三楼西侧。所涉病例从9月3日至9月12日共发病25例,发病高峰在10、11日,临床特征为发热、咳嗽、咽痛和四肢酸痛等,发病有聚集性,病程5 d左右,预后良好,无死亡病例。男性13人,女性12人,男女性别比1.08∶1,年龄分布为7~9岁,平均8.6岁。荧光定量PCR检测结果为甲/乙型流感病毒阴性,AdV阳性,阳性标本经PCR扩增后产物测序为AdV-3和AdV-4。结论结合流行病学调查和实验室检测结果,判断这起学校呼吸道疫情为AdV B3和E4混合感染引起的上呼吸道感染。

Objective To investigate the epidemiological characteristics and causes of an outbreak of respiratory infection in schools.Methods Epidemiological investigation was carried out on respiratory infection cases in schools.Pharyngeal swab samples of children were collected for respiratory tract virus nucleic acid detection,and hexon genes were amplified.Positive PCR result were sequenced.Results All cases were in school,involving 2 classes,12 cases in class 2(3)and 13 cases in class 3(4),all on the west side of the 2nd and 3rd floors of teaching building 2.From September 3 to September 12,a total of 25 cases were involved,with the onset peak on the 10th and 11th.The clinical features were fever,cough,sore throat and aching limbs,etc.The onset was aggregated,the course of the disease was about 5 d,the prognosis was good,and there were no deaths.There are 13 males and 12 females.The males to females ratio is 1.08∶1.The age distribution is 7-9 years,with an average of 8.6 years.The result of fluorescence quantitative PCR were negative for influenza A/B virus and positive for adenovirus.The products of positive samples after PCR amplification were sequenced as AdV-3 and AdV-4.Conclusions The combined result of epidemiological investigation and laboratory tests demonstrated that this epidemic of school respiratory tract infection is an upper respiratory tract infection caused by adenovirus B3 and E4 mixed infection.